I can understand people objecting to treatments funded by the NHS because they reckon it should be lower priority than life-prolonging treatments. What bothers me the most about this is that NHS funding is a convenient place to hide moral evaluations of the treatment in question. Bigbad's post typifies this attitude in spades, with that incredibly dismissive rant against "trannies", "deviants", and more generally anyone who apparently has the slightest negative attitude about being in the heartbreaking position of being unable to have children of your own. It shouldn't be countenanced. The NHS, whatever else it is, should not be a tool for imposing a particular set of moral values on society other than the basic principle that "if you need medical treatment, it should be freely available to you at the point of use".
Clearly the realities of limited funding dictate that for certain conditions either a) more money will have to go the NHS to fund treatment for such conditions, or b) the patients involved may have to contribute some small sum to the cost, or c) the treatment is simply unaffordable and private healthcare is the way to go.
The problem with relying on private healthcare, though, is that it's not like only rich people have what is a real condition, and saying to those without money that "well tough, we don't care enough about your mental health to do anything about it" is equally unacceptable. So that probably leaves a) or b), and since we already have to pay some level of small contributions for certain NHS care I don't see why (b) can't be extended a little, especially for treatments that aren't immediately life-threatening.
Whatever the answer, leave the moral judgments out of it.